Improvement in man-hole covers for oil-tanks



HENRY F1 SNYDER. Improvement in Man-Hole Covers for Oil Tanks.

Patemed m1151119, 1872.

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'HENRY r. `sNr'nnn, oFwILLIAMsPoRT, PENNSYLVANIA.

Specification forming part of Letters Patent No. 124,768, dated March 19, 1872.

Specification describing anImprovement in Man-Holes for Oil-Tanks and analogous structures, invented by' HENRY F. SNYDER, of Williamsport, inthe county of Lycoming, in the State of Pennsylvania.

The improvement relates to the means of securing the cover tightly and safely, and of applying and removing it conveniently.

The following .is a description of what I consider the best means of carrying out the invention: The accompanying drawing forms a part of this specification, and represents the housing or ring around the man-hole, with the several working parts attached thereto; and also,

` on a larger scale, some of the tools or apparatus employed in the manufacture of one portion of the details. It will be understood that the man-hole ring with its attachments are to be secured to the body of the oil-tank or other structure, not represented, by boltin g, riveting, or other ordinary or suitable means.

Figure 1 is a vertical section through the housing and cover with the several securing means. Fig. 2 is a plan view of the same.

Figs. 3 and et represent the means employed in producing a proper end on the swinging link.

Similar letters of reference indicate like parts in all the figures.

I'will denote by the single letterA the entire ring or housing which surrounds the manhole, and forms the foundation for the 'other work, and will designate by A1, A2, 85o., certain specific parts thereof. The top immediately around the manhole is narrowed and smoothed, as indicated by A1, and is adapted to fit very tightly against and imprint itself slightlyv into al soft-metal ring, b, which is formed in the under face of the cover B. The cover is provided with a deep rim, B1, which descends around the rim A1 of the housing, and both the parts are turned or otherwise f1tted so closely as to, guide the cover B in its descent to its seat and cause it to present always the same indented portion of its soft ring ZJ to receive the narrowed -or sharpened edge of the rim A1. The back of the cover B has two lugs B2, which receive a cross-pin, B3. The latter stands in a short vertical slot in a stout cover while compelling the cover B to move with it when it is lifted. and turned over to open the man-hole. C is a post or link, secured to the foundation A by means of a head formed on its lower end,`which is slid laterally into a corresponding recess, and secured by a pin, G. The upper extremity of vthe part C, which I will hereafter term a post, is received within a fork formed inthe end of the lever D, and is pivoted therein by the cross-pin D. The lever D is formed with aprojection downward near the center of its length, adapted to bear fairly and centrally on the,u back of the cover B, between the lugs B2. The lever D and its connections turn on the pivot D in opening and closingthemanhole. Ihave not deemed it necessary to represent the parts when open, believing that its action will be sufficiently clear Vfrom the iigures given with this dev scription. The right hand of the lever D is forked and somewhat deepened, as represented. There is a swinging link, E, turning, in a recess in the foundation-piece A, on a cylindrical pivot, E. Its upper end is both threaded and headed. The method of forming this head without disturbing the threads, and its importance to the full success of the inven tion, will bepresently described.

When the manhole is to be opened, the nut G is turned on the threads so as to raise it. This movement sets the link E at liberty, so that it may be easily turned by the hand, turning on its pivot, and thus swinging out of the forked end of the lever D and leavin g the latter and its connections free to be lifted. When it is desired to close the man-hole thelever D and its connections are brought over into the position represented, and the lip B1L guides the cover down to its true position. When the sharpened or narrowed upper edge of the rim A1 has entered properly to its seat in the lead or other soft-metal ring b, and the leverD has pressed it gently down as well as can be done by the force of the hand, the link E is swung up again into the position represented, and the nut Gr screwed down by a wrench or other suitable means. To avoid a loss of the nut Gr by unscrewing it too far, I head or rivet the upper end of the bolt E; and to avoid injury to the threads below, I take care to inclose the threadswithinatemporary nut, madein pieces, as shown.

It is important to 'provide in my device against the opening the man-hole by unauthorized parties. I attain this end by the employment of a transverse key, H, inserted crosswise through the lever D, outside of the nut E, and securing it in its position by a padlock, I, indicated in plan in Fig. 2. The plan view, Fig. 2, shows the upper surface of the manhole cover B, strengthened by radial ribs. This is not essential to the success of the invention, but it obviously allows the cover to be sufficiently strong with less material than would otherwise be required.

I claim as my invention- 1. The lever D and swinging link E, arranged and operating relatively to the cover B and ringA A1, as and for the purposes herein spec- Witnesses:

T. C. ROGERS, H. D. HEIsER.

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